Talking about Murder Mysteries with some friends got me talking about traps and puzzles, and the pitfalls (heh, whoops) that can come with them at the gaming table. Today I want to go over them briefly, and give you some pointers on how to employ them.
Dice Traps/Puzzles and Thought Traps/Puzzles
First off, in gaming puzzles come in two varieties: Dice and Thought.
Dice traps/puzzles are those that only need a dice roll to figure out. For example, finding a secret door is often a dice puzzle. The player doesn't need to do anything, except beat the threshold to spot the hidden door. Once they've made the roll, they've found the door and beaten the puzzle. Most locks are like this for thieves in games like D&D. You make one check, you pass the puzzle. Hurray team.
Thought traps/puzzles tend to not need dice rolls at all, but rather require the PCs to take actions that are out of the ordinary. Figuring out that the various crayons need to be arranged like a rainbow to unlock and reveal a hidden door would be an example of this. Sure, a dice roll may be used to find hints, but ultimately a player has to think of - and try - arranging the colors in the right order for it to work.
Dice Puzzles Should NEVER Be Mandatory
I want to be clear. At no point should progressing through an adventure or some other part of your game be solely dependent on the PCs' ability to pass a Dice Puzzle.
Because what do you do when the PCs fail the roll? If your answer was "let them try again" then why have them roll in the first place. If your answer to that was because it's more about how long it takes them (i.e. picking a lock while holding off waves of badguys) then this isn't meant for you.
Simply put though, if you hinge your game on a dice roll coming up a certain way at a certain time, one of two things is going to happen: It will happen way earlier than you want it too, breaking all of your plans. It will never happen, getting your game stuck in the bog of no progress until everyone goes home pissed off. I mean, sure, maybe the dice roll will work at the right time and that'll be great - good job everyone - but dice do strange things, and it's not worth the risk.
Remember: Your Players Don't Know The Solution
With thought puzzles the trap I see most GMs fall into is one of perspective. To the GM it is super obvious that Clue A and Clue B work together to make Solution C. After all, the GM knows the solution, and likely developed the clues after making the solution to point to it.
Unfortunately, the PCs do not know the solution. And as such, what is obvious to you may not be obvious to them. And if the solution doesn't spring to mind, the PCs could get frustrated looking for answers all the while you're getting frustrated because they have such huge clues and if you say more you're just giving it away.
I recommend having a few clues ready - more than the ones you are giving for free - that you can dole out if the players get stuck, or if they ask for help via an Insight check or something like that. Worst case, you can always suggest that they come back later - provided your story allows for that, anyhow.
Don't Hide Big Bads Behind Puzzles
Much like with the dice thing, let's be honest here. If you hide a Big Bad or some other big item behind a puzzle one of two things is going to happen. 1) the party is going to bypass the puzzle right away and getting to the big bad fight way too early - or getting the key item way too early ruining all your other plans. 2) the party is going to ignore the puzzle completely and ruing everything.
Obviously the third option of the party does it "right" could happen, but much loike with the note about dice puzzles it's not worth the risk.
The easiest way to do this is to take a page from videogames. If the PCs are in a maze and shouldn't fight/find what's behind the puzzle until X time, then make it so they can't do so until X time. Lock a key thing down, and declare it a lock that can't be picked for whatever reason. Then just don't forget to put the key at whatever key thing the PCs need to do before the puzzle happens.
Yes it is a little direct, but it also keeps things in line. As far as not giving the PCs a chance, I mean, I'm not saying they can't go and try to steal the key and come back fast. I'm just saying their means of unlocking things aren't feasible here for whatever reason. Most PCs will get the hint.
Be Open To Alternative Solutions
Fun fact: I hate riddles. I hate riddles with a passion. I hate riddles because I am bad at riddles - at least in part - but what really gets me with them is when you have an answer that meets every criteria the riddle sets forth and am still told I'm wrong.
Because of this you want to be very careful with your wording of puzzles, but you also want to be open to alternative solutions. Sure, maybe you didn't intend for your puzzle to have that solution, but if it is awesome and it fits, just give the win over. Especially if the actual solution isn't occuring to the players.
Death Traps Should Have More Than One Way Out
By the same idea, any trap that can kill someone should have more than one way out. Again, be open to creative thinking and solutions, but make sure you plan more than one way that the thing can be escaped disarmed.
If nothing else, the person who built the trap probably left themselves a way out, right? Right.